Primary and secondary domains clarifications

A question popped up if I'm interpreting it correctly what primary and secondary domains can be.

From the examples in the books it looked like to me that primary domains are only broad concepts while secondary domains are narrow concepts.

Is that so correcct?

Thus a primary domain of bows / archery is not valid, and a secondary domain of life or a secondary domain of death also not, or is there no such "rule" and ALL concepts can be primary and/or secondary domains?

Your interpretation is correct. Make sure to keep the subjects for your primary domain broad enough to encompass lots of leeway in thinking. NGoM is a Strategic RPG and you are encouraged to bend the rules for domains. Make sure you talk with your GM/ group about interpretations.